Nonprofit Vote and the U.S. Elections Project have released a thorough study of 2016 voter turnout. See it here. The 2016 November turnout was 60.2%, which is better than the November 2012 turnout of 58.6, but not as good as the 2008 turnout.
The Report has a great deal of data that shows how characteristics of state election systems relate to turnout. Clearly, the most effective idea for increasing turnout is for states to allow election-day registration. The report also shows that states that provide few choices on the ballot have lower turnout. Thanks to Rick Hasen for the link.